Track for self-laying track type vehicles



0ct.`15, 1946. c. w. L EGUILLON ET AL 2,409,502:

TRACK FOR SELF-LAYING TRACK TYPE VEHICLES Filed Jun'e 22, 1943 Patented Oct. i5, 1946 TRACK FOR SELF-LAYING TRACK TYPE VEHICLES Charles W. Leguillon and Alvin S. Krotz,Akron, Ohio, assignors to The B; F. Goodrich `Com pany, New York, N. Y., a corporation of New York Application June 22, 1943, serial No. 491,760

6 Claims.

This invention relates to track for self-laying 4track type vehicles, and more especially to track blocks therefor.

Inthe use of self-laying track typeV vehicles it has been found that track blocks of metal could be usedV to advantage on soft terrain but these have not provided the desired traction on hard pavements or the like. Furthermore, their use has been limited to slow vehicle speeds. Track blocks having tread surfaces of resilient rubber or other rubber-like material have been found to provide greater traction on hard pavements and the like, and to provide more quiet operation at higher speeds with less damage to the pavement. Such blocks as constructed heretofore, however, have been found to suffer rapid deterioration due to cracking and spalling of the resilient composition "especiallywhere it has been attempted to employ synthetic rubber or rubber-like compositions for the resilient face of the block. Furthermore, the useV of tracks having resilient treads has been confined to light vehicles due to tendency of the resilient material to spread and separate under heavy pressure.

The present invention aims and other difficulties. A

The principal objects .of the'present invention are to provide a composite track block structure having good traction properties on hard pavement or soft terrain, `toprovide for retaining` the to overcome these resilient material and preventing excessive spreading and cracking or spalling thereof, to provide high mechanical strength with adequate resilient cushioning, to` provide cushioning of j the bogie wheels, toprovide a resilient support directly from the'bogie wheels tothe ground, to

provide for' interlockingl of Vthe resilient rubberlike material with the metal without requiring bondingfto provide a construction in which the resilient rubber-likematerial may be moldedwith a `minimum of mold equipment-to provide for torsional cushioning of the hinge pins, toV facilitate assembly and disassembly of the'track, to provide simplicity of construction, and to provide for convenience of manufacture.

These and other objects ywill appear from the following description and thev accompanying drawing.` i

Of the drawing, y i Fig. 1 is a side elevation of a track constructed in accordance with and embodying the invention, and showing driving, guiding and bogie wheels of a vehicle, parts being broken away.

Fig. 2 is atread surface View of a` portion of the track of Fig.v 1.

Fig. 3 vis a sectional view thereof, taken on line 3-3 of Fig. 2.

Fig. 4 is a sectional view taken on line 4--4 of Fig. 2.

Fig. 5 is a cross-sectional View taken on line 5 5 of Fig. 2, the driving sprockets and guiding wheel being shown' in dot and dash lines.

Fig. 6 is a tread `face View of a modified form of the invention, parts being broken away.

Fig. 7 is a cross-,sectional view thereof taken on line 1--1 of Fig. 6.

Fig. 8 is a sectional View thereof, taken on vline 8-8 of Fig. 6, parts being broken away.

Fig. 9 is a sectional View thereof taken on line 9-,9 of Fig. 6, `parts being broken away.

Fig. l0 is a sectional view taken on line l-ID of Fig. 6, parts being broken away.

In accordance with the invention a track is formed of track blocks hinged to each other and provided with a retaining wall whchsurrounds a body of resilient cushioning material such as rubber having a high tractive coefficient. The enclosed resilient material may Contact either with the ground to provide cushioning and traction or with thev bogie wheels which support the Vehicle `to provideicushioning, or with'both, and in the preferred form of the invention, the resilient material extends continuously through the track block from the tread face to the bogie wheel contacting face thereof so that the vehicle is supported on a column of rubber from the tread face of the track. The hinge pins are preferably provided with resilient torsion bushings extending through the track blocks and providing for fleXure ofthe track without sliding friction and for cushioning of the track longitudinally.

Referring to the drawing, and first to Figs. 1'to 5 thereof, the track I0 is trainedabout a driving wheel il having sprocket teeth l2, a guiding vwheel I3', and load supporting bogie wheels I4, 5,

i6, l1. The track comprises a series oftrack `blocks-H3 pivotally connected to each other by thingie pins I9.-

`ing the ground; and an oppos1te Wheel-engaging Each track block has a tread face 25 for engagface 26. Acentral area of the track block is surrounded by substantially vertical walls 21, 28, 29, 3l)v of metal which .are joined to each other at their ends and extend substantially normal to the tread face of the block from the tread face to the wheel-engaging face to dene a boX-like structure. A web 3l extends parallel to the tread face between the vertical walls to which it is sercuredfand divides the central enclosed area to 3 provide a cavity 32 open at the tread face and a cavity 33 open at the wheel-engaging face for receiving resilient material.

For connecting the track blocks to each other, a plurality of ears 35, 36, 31 are provided at one end of each block extending longitudinally from the wall 29 in spaced-apart relation, and the Wall 3E) of the block is formed with a pair of knuckles 40, il for engaging between the ears in intercalated relation. The knuckles lill, 4I are formed with aligned apertures for receiving torsion bushings 42, 43, and the ears 35, 36, 31 `are formed with cross apertures of smallerbore in alignment with the apertures of the knuckles for receiving a hinge pin 44.

The bushings a2, 43 each comprise an inner sleeve l5 of metal flattened along one side, as at 46, a bushing l1 of soft vulcanized rubber or similar-rubber-like material thereabout and preferably bonded thereto, as by vulcanization, and a split outer bushing 9 of metal bonded to the rubber-like material. The outer bushing 49 is preferably of semi-cylindrical bushing sections 119cv, 49h. The bushings are forced into the apertures of the knuckles with the resilient bushing under radial compression. The hinge pin 44 is formed with a flat 5B along one side throughout its length to prevent its turning with relation to the inner sleeves l5 of the torsion bushings through which it slidably extends. The ends of the hinge pin are secured to the ears 35, 31 as by taper pins 5I, 52 passing through the ears and the pin, or by other suitable fastening means. The arrangement is such that when one block is rotated about the hinge pin 44 of the adjacent block, the resilient bushing material is tensioned by the torsional movement.

For driving the track, each block extends at the sides of the box-like structure to provide wing portions 60,' 6l which provide additional weightsupporting areas effective to support the vehicle on soft terrain but above the normal tread surface of the block, and these wings are provided with through apertures 32, 63 for engaging the sprocketteeth of the driving wheel. Webs 64, 65 formed on the tread face ofthe wings act as braces and also provide traction in soft ground 'into which they embed.

For guiding the track, upstanding guide lugs S6, B1 are formed integrally with the metallic frame and project on the wheel-contacting face of the block to engage over the sides of the guide wheels.

To provide greater traction on hard pavement, the tread face cavity 32 is filled at least flush with the tread faces of the surrounding metal walls with a resilient material having a high coeliicient of friction with such pavement and preferably with a body of soft vulcanized rubber or other rubber-like material although a filling of brous material in the form of woven cloth or cord 1walls 21, 28, 29, 30 may have projections 10 formed thereon or reentrant grooves 1| formed therein for holding the filling in place. Alternatively, or in addition to the projections and grooves, the filling may be adhered to the metal as by a bond resulting from vulcanization and for this purpose the metal parts may be electroplated with brass and the rubber vulcanized thereto.

The arrangement is such that the enclosing walls of metal protect the resilient lling material from spreading excessively under heavy loads and from cracking and splitting or spalling at the margins under such loads while the metal enclosing walls will wear away at least as fast as the filling in use so that the lling is always available at the tread surface for providing increased traction. The preventing of cracking and spalling is of especial advantage where the filling is of vulcanized synthetic rubber or rubber-like materials not having great resistance to such splitting and spalling action.

For cushioning the track from the bogie wheels, an additional filling of similar resilient material, such as soft vulcanized rubber or other rubber-like material may be provided in the cavity 33 at the wheel-engaging face of the block and extending at least as high as the edges of the surrounding metal walls at such surface, and this lling may be similarly retained by projections, grooves, or bonding.

If desired for operation only on soft ground the nlling of the cavity 32 may be omitted and the walls 21, 28, 29, and 30 will act as grousers while the resilient filling of the recess 33 will provide quiet operation and cushioning of the bogie wheels. Conversely, the cavity 32 may be lled with resilient material for providing cushioning of the track and increased traction and the lling of the recess 33 may be omitted.

Forproviding cushioned support of the bogie wheels directly from the road, the iilling of resilient material in the cavities 32 and 33 may be integral and continuous so as to provide a solid column of rubber or other resilient material extending between the retaining walls 21, 28, 29, 3l] from the tread face to the wheel-contacting face. For this purpose the web 3l may in some lcases be omitted entirely. It is preferred, however, to retain'the web 3l adjacent the retaining sidewalls for strengthening them and to provide apertures 15, 16 therethrough of considerable size through which the filling extends. With this construction, the weight of the bogie wheels will deform the resilient material and cause it to bulge beyond the normal tread plane at the tread face of the track whereby it will project beyond the retaining walls and the bogie wheels will be supported by resilient material directly from the ground despite the presence of the metal walls at the tread face.

Forproviding space for ow of the resilient material under pressure, the filling at the tread surface may be formed with fiow cavities, such as the chevron-shaped grooves 11.

In the modified form of the invention shown in Figs. 6 to 10, the track is formed of track blocks each having a generally rectangular body defined by retaining Walls I, IUI, |02, |03 normal to a face of the track and joinedat their corners to provide a box-like structure extending from the tread face I 04 to the wheel-contacting face |05 and providing a space for a filling |06 of resilient material such as vulcanized rubber or other rubberlike material, as in the form of the invention of Figs. 1 to 5.I A partition lll1, parallel to the tread face, extends between the retaining walls and may be formed Vbe'formed on the partition through for engaging the sprocket teeth of a driving wheel for driving the track.

For guiding the track, a pyramidal projection VH .i is formed integral with the metal frame Vof theV block' at its center for engaging between guide wheels. The projection may conveniently Il and extends 'through' the resilient Vfilling above the wheelengaging face of the track.

For hinging the track blocksto each other, one end of each block is formed with a pair of knuckles Sie, II'Iformed from .the wall |63 andlhaving aligned apertures of large bore for receiving torsion bushing structures, each comprising a resilient torsion bushing |.IB or IIS of rubber or other rubber-like material bonded to a shaft extending through and beyond both bushings, and Semi-cylindrical outer shell members |2I, |22 bonded about the resilient bushings. The bushings i8, I I9 are spaced apart as are the knuckles Ht, I|`I to provide space for a shaft retaining clip of U-shape.

The opposite end of the track block is formed with bifurcated jaws I 25, |21 at its opposite sides and a central jaw |28 of similar construction. A pair of retaining blocks |29, |30 are adapted to fit between the jaws |26, |21 respectively, where they are retained by screw bolts |3|, |32 passing through the blocks and the jaws. The blocks |29, i3 have aligned apertures for receiving the ends of the shaft or hinge pin lil which is Fixed thereto as by taper pins |33, |34 passing through` the hinge pin and the blocks. At the center of the track the U-shaped clip 1125 is looped about the hinge pin between thetorsion bushings, and its ends are inserted between the jaws |28 where they are retained by a screw bolt I 36 passing therethrough. The arrangement is such that adjacent blocks may be separated by removing Ythe three screw bolts |3I, |32, |36.

The resilient torsion bushings are inserted in the knuckles under radial compression together with the hinge pin, the radial compression being sufcient to prevent turning of the outer shell members in the knuckles during use. The U- shaped clip employed at the central position between the knuckles may be inserted about the hinge pin after the bushings and the shaft have been pressed into position by pressure applied axially thereof.

The resilient filling material may be molded in place in either of the track blocks shown by the use of plain mold plates engaging the tread face and the wheel-engaging face respectively o'f the block to confine the material during vulcanization. A convenient molding procedure isby injection of the plastic material through an opening in one of the mold plates while the plates are bolted to the faces of the block. Heat may then be applied to the block as by placing the block and theenclosing mold plates in an open stearnv vulcanizer. If it is desired to provide the filling extending above the tread face or the wheel-engaging face of the block, cavities may be provided in the mold plates for accommodating the excess material.

The metallic frames of the track blocks shown are readily cast, forged, or assembled and welded, and require a minimum amount of machining.

Variations may be made without departing 6 from the spirit; of the invention as it is defined by the following claims.

- We claim:

1 1. A track block for a self-'laying` track type vehicle in which a series of blocks are hingedly connected; said block comprising a metal frame .having retaining walls extending. substantially toa face of the block, a partition spaced from said face dividing the space betweensaid retaining walls, said partition being apertured to provide a communicating opening therebetween, and a `filling of resilient material in said space and extending between the tread face and the wheelcontacting face of the block;

2. A track block for a self-laying track type vehicle, said block comprising a metal frame having a retaining wall extending rigidly about the entire periphery of `the block and substantially nto vtheiuppe: andilower faces ofthe block, partition means integral with said frame between its upper and lower faces for securing a filling thereto, said partition means having openings therethrough for accommodating said filling, and a filling of resilient rubber-like material retained by said wall, said filling being substantially entirely within said wall and extending through said partition with upper and lower faces of the filling substantially ush with and exposed at the upper and lower margins of the wall over a substantial area of both said faces of the block and providing load transmission through the filling directly from face to face thereof while being restrained from spreading by said retaining wall.

3. A track block for a self-laying track type vesubstantially entirely within said wall and extending through said partition withl upper andV lower faces of the filling substantially flush with and-exposed at the upper and lower margins of the wall over a substantial area of both said faces of the block and providing load transmission through the filling directly from face to face while being restrained from spreading by said retaining wall, and guide means integral with said `frame and said partition for aligning the block with a track-engaging wheel.

`depth by said retaining wall, and guide means within said retaining wall and integral therewith for aligning said filling with a wheel of the vehicle, said guide means providing support for said lling.

5. A track block for a self-laying track type vehicle, said block having opposite wheel contacting and tread faces and comprisingl a retaining Wall extending rigidly about the wheel contacting portion thereof and substantially toboth faces of the block, a lling of resilient rubber-like material retained by said Wall, said filling being exposed over a substantial area of both wheel-contacting and tread faces of the block providing load transmission through the filling directly from face to face thereof While being restrained from spreading throughout substantially its entire depth by said retaining wall, partition means within said retaining Wall, said partition means having openings therethrough for accommodating said filling, and guide means integral with said partition means for aligning said filling with a wheel of the vehicle.

6. A track block for a self-laying track type vehicle, said block having opposite Wheel contacting and tread faces and comprising a retaining Wall extending rigidly about the wheel contact- 8 ing portion thereof and substantially to both faces of the block, a filling of resilient rubber-like material retained by said Wall, said filling being exposed over a substantial area of both wheel-contacting and tread faces of the block providing load transmission through the filling directly from face to face thereof While being restrained from spreading throughout substantially its entire depth by said retaining wall, partition means within said retaining wall, said partition means having openings therethrough for accommodating said filling, guide means integral with said partition means for aligning said filling with a wheel of the vehicle, and wing tread portions integral with said retaining wall and extending laterally of the Wheel-contacting face for increasing the area of contact with the ground.

CHARLES W. LEGUILLON. ALVIN S. KROTZ. 

